Carburetor



R SHIPMAN CARBURETOR Nov. 7, 1944.

2 Shets-Sheet 1 Filed Dec. 20 1940 Nov. 7,' 1944.

R. SHIPMAN CARBURETOR Filed Dec. 20, 1940 2 sheets-sheet 2 Patented Nov. 7, 1 944 UNITED STATES PATENT OFFICE- 2,362,163 CARBURETOR Ralph Shipman, Sunbury, Pa.; Raldo E. Shipman and I. Kenneth Shipman, executors of said Ralph Shipman, deceased, assignors, by mesne assignments, to said Raldo E. Shipman and said 1. Kenneth Shipman, as joint tenants Application December 20, 1940, Serial No. 371,041

11 Claims. (01. 261-12) This invention relates to carburetors and more particularly to carburetors of the type commonly employed for supplying a combustible mixture to gasoline engines.

a As is well known, the efficiency of such engines depends upon the fuel and air being thoroughly and intimately mixed together. The better and more complete this mixture, the greater the fuel economy.

In producing a fuel mixture by means of the usual jet or spray type carburetor, there are usually present in the mixture heavier particles of fuel which have not been completely atomized or vaporized and which therefore do not burn with the greatest efiiciency.

One object of the present invention is to pro.- vide improved means for thoroughly evaporating and vaporizing such heavy particles, so as to produce the best possible admixture thereof with air. To this end, I propose to provide means for throwing out and trapping these heavier particles again to the current of air and are each time ever,- I contemplate combining the above mentioned recirculating means with a carburetor of the usual jet type, so that portions of the mixture generated in the carburetor itself are continuously recirculated as described.

A further .object of the invention is to provide improved heating means so constructed as to supply heat to 'the surface employed for vaporizing the fuel particles while avoiding the heating of the passages through which the fuel mixture itself flows to the engine.

Still another object of the invention is to provide improved means for air bleeding the fuel jet, so that, as the suction increases on this jet, progressively larger amounts of air will be introduced.

With the above and other objects in view, and

to improve generally upon the details of devices of this character, the invention consists in the construction and arrangement of parts hereinafter described and claimed, and illustrated in the accompanying drawings, in which:

Fig. 1 is a side elevation of one embodiment of the invention, parts being broken away and a fragment of the engine manifold being shown;

Fig. 2 is a plan View of the device shown in Fi 1;

Fig. 3 is a section substantially on the line 3--3 of Fig. 5 looking in the direction of the arrows, showing a bottom or inverted view of the upper portion of my improved carburetor;

Fig. 4 is a transverse section substantially on.

the line 4-4 of Fig. 1, looking in the direction of the arrows;

Fig. 5 is a vertical central section substantially on the line 5--5 of Fig. 1, looking in the direction of the arrows;

Fig. 6 is a similar section taken substantially on the line 6-6 of Fig.2, displaced from the section shown in Fig. 5, the lower portion being broken away;

Fig. 7 is a plan view of the annular assembly of parts disposed immediately below the line 3--3 of Fig. 5; n

Fig. 8 is a side elevation of the interior parts of the carburetor, including the venturi, as they appear when removed from the body; and

Fig. 9 is a fragmentary section on an enlarged scale substantially on the line 9--9 of Fig. 2,

looking in the direction of the arrows.

Referring to the drawings in detail, I have shown, by way of illustration, a complete carburetor comprises a cylindrical body or housing I, open at the top, as indicated at la. Associated with this body in any desired manner is the usual or any suitable float chamber 2, to which liquid fuel is supplied through a suitable pipe (not shown), it being understood that there is a float (not shown) in this chamber which serves to maintain the liquid fuel therein at a constant level. I r

A fuel tube 3 communicates with the float chamber 2 and extends into the interior of the body I, where it terminates in a fuel jet at the throat of a primary venturi 4.

This primary venturi discharges at its lower end into the throat of a larger secondary venturi 5, which fits snugly within the body or housing I.

At the lower or outlet end of the venturi 5 is,

a conical bafiie 6, coaxial with the venturi and preferably having concave sides, as shown in Fig. 5. The purpose of this will be hereinafter explained. 7

Below the carburetor is disposed my improved heating means which is designated in its entirety by the reference numeral 1. This comprises a cylindrical section, conforming with the periphery of the lower portion lb of the carburetor, and as shown in Fig. 4, having a central core 8. Surrounding this core are a plurality of concentric annular walls 9, constituting with the core 8 and the outer shell of the heater a continuous sinuous passage for hot gases, these gases entering at l i, passing around the core 8, and thence along inside of the outer wall and bein discharged at H2. The intake and outlet openings H and 12 extend through a bolting flange ill by means of which the openings may be connected with suitable supply and discharge pipes.

Interposed between the inner and outer turns of the above described passage for hot gases is an annular opening i3, which passes entirely through the heater, axially thereof, as clearly shown in Figs. 4 and 5. This annular opening 13 constitutes the passage for the flow of fuel mixture from the venturi 5 down to the intake manifold of the engine.

In order to insulate the opening or passageway l3 from the heat of the hot gases coming into the heater at ii, I preferably provide between this opening and the passageway for the hot gases a second wall 5a which is slightly spaced from the wall 9 and forms therewith a dead air space 9?) (see Figs, 4 and 5).

At the top of the heater 1 is a well, having a bottom formed by the upper surface M of the heater and having an upstanding rim l5.

Immediately below the heater is a fitting it in which is carried the usual throttle valve l'l, mounted on a shaft E8 to which is secured an operating arm F9. The fitting i5 is secured to the heater 7 as by means of screws 15, a suitable gasket it?) being preferably interposed between them.

Secured to the lower end of the fitting it as by bolts 2 i is the intake manifold 25.

Referring now to Fig. 5, it will be noted that the conical bafiie 5 extends down below the top of the rim i5, and is slightly spaced therefrom, as indicated at 22. A plurality of tubes 23 (four being illustrated) are secured to the baffle 5 and project down through this baffle into the well beneath the same. From the well these tubes pass upwardly through the body of the venturi 5 and terminate at their upper ends in nozzles 2 disposed at the throat of the venturi,

The interior surface of the lower portion of the body I of the carburetor is preferably of concave section, as shown at 25 in Figs. 5 and 6, and immediately below this concave portion is the assembly of annular parts indicatedin Figs. 5 and 6 and best shown in Fig. 7. This assembly comprises three superposed rings 26, 2! and 28, the rings 26 and 28 being relatively thin while the ring 21 is relatively thick. The ring 23 has at its inner edge an upstanding axially disposed flange 29, which forms in eifect a continuation of the outer wall of the opening l3 (see Figs. 5 and '6), and projects slightly above the ring 26.

This ring 26 has a series of four openings 26a, spaced therearound, while the ring 21 has a similar series of pockets 21a formed in its inner edge, each pocket having a radially extending notch 27b registering with one of the holes 26a. The ring further has a plurality of lugs 261) at its inner edge which lugs bear against the annular flange 29, whereby the inner periphery of the ring 25 is slightly spaced from this flange, as shown at 35 in Fig. 7. Screws 3| pass through the flanges lb at the lower edge of the carburetor body and through the ring assembly and into the heater '1, thus securing the parts rigidly together (see Fig. 6).

Extending longitudinally through the walls of the lower portion of the carburetor body are a plurality of conduits or passages 32, four of such passages being shown, and these being preferably formed in ribs 33 projecting from the body, in order to lighten its construction. The lower end of these passages or conduits 32 registers with the holes or openings 26a in the ring 25 and the upper end of each of the conduits terminates in a jet or nozzle 34 at the throat of the venturi 5.

Thus by reference to Fig. 3, it will be seen that at the throat of this venturi are illustrated a series of eight nozzles, four of them being connected with the tubes 23, and the other four being connected with the conduits 32, the nozzles of these respective groups preferably alternating. In view or" the foregoing, it will now be understood that a continuous passage is provided from the interior of the lower portion of the carburetor body through the narrow space 3%, pockets 27a, notches 2Tb, openings 26a, and conduits 32 to the nozzles 34, and that similarly, a passageway is provided from the interior of the carburetor body through the annular opening 22 and thence up through the tubes 23 to the nozzles 24.

As is well understood, the pressure existing at the throat of a venturi is less than that existing at its discharge or delivery end. Thus the pressure at the nozzles 24 and 33, disposed at the throat of the venturi 5, is lower than that existing at the bottom of the carburetor body adjacent the heater. Consequently, during the operation of the engine, a suction is created at the nozzles 24 and 34 which tends to draw fluid up through the tubes or conduits 23 and 32.

IAS air rushes down through the primary carburetor the fuel is atomized at the jet 3 and, passing downwardly into the secondary venturi 5, impinges against the conical bafiie 6, where it is deflected laterally. The heavier particles of fuel in the mixture will therefore strike against the upstanding rim l5 of the well and, collecting on this rim, will trickle down through the annular opening 22 into the well, such movement being assisted by the reduced pressure created in the well by the action of the tubes 23. These heavier portions, thus entering'the well, come in contact with the hot surface E4 of the heater, and are thus vaporized. The vapor is then sucked up through the tubes 23 and delivered from the nozzles 24 into the venturi. If unvaporized fuel accumulates inthe well until it reaches the level of the'lower ends of the tubes 23, it is drawn up into the tubes and delivered at the nozzles 24 into the air stream again, where it is still further broken up.

Similarly, any heavy particles'which pass over the rim IE will impinge against the concave surface 25 and trickle down-the same, whence they pass through the narrow opening 30 down into the pockets Zia and slots 21!). From there, the heavy fuel is either vaporized by the heater and passes up through the conduits 32, or if still liquid, is

'sucked-upthrough these conduits and delivered to the nozzles '34, where his again mixed with the air stream.

The fuel mixture from which the heavy unvaporized particles have thus been separated, as above described, passes down through the opening 3 tothe engine manifold. While I have referred to the'heavy particles being vaporized and returned to the venturi, the arrangement shown has distinct advantages even though a heater is not employed. In this case, the heavier portions of the fuel mixture will be thrown out into "the central and annular well structures, as described and will be sucked up and delivered into the venturi through the nozzles 24 and 34, and thus again subjected to the air stream. In this way, it is quite possible that the same heavy portions of fuel will be recirculated through the venturi a number of times until the particles thereof are evaporated or reduced in size to such an extent as to be capable of intimately mixing with the air.

Further-more, while I have shown and described my improved recirculating means as employed in connection with a primary venturi for forming the fuel mixture, it will be understood that the fuel mixture may be formed in any other way or at any other desired point. usual or any desired type of jet carburetor is employed, I contemplate inserting my improved circulating means, including the venturi 5, at any desired point within a housing or pipe extending "between the carburetor and the engine, either with or without a heater, so as to thoroughly break up the particles of fuel and cause them to effectively mix with the air so as to produce an 'e'fficient charge.

Referring now to Figs. 8 and 9, I have illustratedan improved means for air bleeding the fuel jet.

In my c'opending application Serial No. 371,042, filed December 20, 1940, I have illustrated a plurality of weighted valves, each controlling a restricted air port communicating with the jet tube, and so arranged that, as the suction on this tube increases, these weighted valves automatically open in succession.

In the present arrangement, I employ the same general principle, but use a modified arrangement of weighted valves.

Formed in the body of the venturi is a valve chamber 35 closed at its upper end by a plug 36 and containing weighted valves 31 and 41. The valve 31 preferably has a tapered lowe end 38 resting on a seat closing an air passage 39 communicating with the chamber 35, and has extending axially through the center thereof a restricted air port 40. The valve 4!, which is relatively light, has a conical lower end 42 resting on a seat which closes the port 40, the two valves thus being superposed. Passages 43 and 44 connect the port 39 with an upstanding intake tube 45 rotatably mounted at its lower end in the body of the venturi 5 and having its upper end bent over and extending laterally, as shown in Figs. 2 and 6. The open end of the tube 45 is disposed immediately above the intake end of the venturi 4, andmay be swung transversely thereof, as indicated by the double headed arrow in Fig. 2. A passage 45 connects the valve chamber 35 with the fuel tube 3. The lower end of this fuel tube is connected in any suitable way, as by means of a fitting 3a, with the float chamber 2, this fitting being received in a socket 3b. The fitting 3a is intended to be equipped with a plug having a restricted fuel passage similar to that il- Thus, where the lustrated in my above identified prior co-pending application.

From the foregoing, it will be seen that as the suction increases on the fuel jet 3, the valve M will first be lifted from its seat, thus permitting air to flow in through the passage'39 and restricted port 40, into the fuel tube. As the suction still further increases, it will finally reach a a point where itwill lift the relatively heavy valve 31 from its seat and permit air to enter the valve chamber directly through the larger port 39, whereby an increased amount of air is thus supplied.

,While in my said copending application above identified I employ interchangeable plugs .hav-

ing restricted air ports of assorted sizes, in order to regulate the proper relation between the amount of air and the amount of fuel admitted to the fuel jet under different conditions, I achieve the same end in the present construction by virtue of the adjustable .air intake pipe 45. By swinging this pipe so "as to move its open end transversely nearer or further away from the axis of the venturi, I can vary the amount of suction applied tosuch pipe and thus vary the tendency of air to enter the same when the valves 31 and 4| are lifted. In other words, by adjusting this pipe, I am able to regulate, as desired, the flow of air therethrough into the fuel tube. 7

What I claim is: i

l. The combination with a housing, of a down draft venturi'mounted therein, and means independent thereof for feeding thereto a mixture of liquid fuel and air, of a well directly beneath the lower end thereof and spaced therefrom, a second well surrounding the first, said wells being disposed within said housing and spaced apart so as to provide between them an outlet passage for the fuel mixture, and means for trapping in both wells the heavier particles of fuel contained in said mixture.

2. The combination with a down draft venturi, and means for feeding fuel mixture thereto, of a well directly beneath the lower end thereof and spaced therefrom, a second well surrounding the first, said wells being spaced apart and having between them an outlet passage for the fuel mixture, means for throwing out andtrapping in both wells the heavier particles of fuel in said mixture, and an independent conduit extending from each well into the throat of said venturi.

3. The combination with a housing, of a down draft venturi mounted therein and means for causing a flow therethrough of a mixture of liquid fuel and air, of a central well disposed directly beneath the same within said housing, an annular well structure surrounding said central well and spaced therefrom to provide an annular passage for the fuel mixture, and bafiie means within said housing for throwing out and trapping both in said central well and annular well structure the heavier particles of fuel contained in said mixture.

4. The combination with a housing, of a down draft venturi mounted therein and means independent thereof for causing a flow therethrough of a mixture of liquid fuel and air, of a well disposed in said housing directly beneath the same and arranged to trap the heavier particles of fuel contained in said mixture, means providing an annular passage within said housing around said well for the discharge of fuel mixture, and heating means for vaporizing the fuel in said well comprising an annular fluid conduit beneath said well concentric with but insulated from the walls of said annular passage.

5. A down draft carburetor comprising a body open at its upper end, a primary ven'turi in said body having a fuel jet in the throat thereof, a secondary venturi within said body below said primary venturi into the throat of which the primary venturi discharges, a nozzle discharging radially into the throat of said secondary Venturi, and a conduit wholly within said body connecting said nozzle with a point Within the carburetor below the outlet end of said secondary venturi.

6. A down draft carburetor comprising a body open at its upper end, a primary venturi in said body having a fuel jet in the throat thereof, a secondary venturi Within said body below said primary venturi into the throat of which the primary venturi delivers, and means Wholly inside of said body for continuously recirculating through said secondary venturi portions of the fuel mixture delivered into the throat thereof by said primary venturi.

7. A down draft carburetor comprising a body open at its upper end, a primary venturi in said body having a fuel jet in the throat thereof, a secondary venturi also within said body and into the throat of which the primary venturi delivers, and means wholly inside of said body for continuously returning to the throat of said secondary venturi the heavier portions of the fuel mixture issuing from the lower end thereof.

8. The combination with a down draft venturi, means for feeding fuel mixture into and through the same, and means for delivering said mixture into an engine intake manifold, of a central well beneath the lower end of said venturi, an annular well surrounding said central well and spaced therefrom to provide a passageway, means for trapping in both wells the heavier particles of fuel contained in said mixture, and a heating element disposed beneath both of said wells and having a passageway registering with that between said wells.

9. The combination with a housing, open to atmosphere at its upper end, of means within said housing, including a fuel jet, for producing a fuel mixture, means for connecting the lower end of said housing with an engine intake manifold, a down draft venturi between said jet and connecting means and through which said mixture passes, a well disposed directly beneath the lower end of said venturi and between the same and said connecting means, means for trapping in said well portions of said fuel mixture, and means within said housing for sucking up from said well and delivering into the throat of said venturi the portions thus trapped.

10. The combination with a housing, open to atmosphere at its upper end, of means within said housing, including a fuel jet, for producing a fuel mixture, means for connecting the lower end of said housing with an engine intake manifold, a down draft venturi between said jet and connecting means and through which said mixture passes, a well disposed directly beneath the lower end of said venturi and between the same and said connecting means, means for trapping in said well the heavier particles of fuel in said mixture, means for heating said well to yaporize said heavier particles, and means for returning the thus vaporized fuel to the throat of the venturi, said means including nozzles disposed radially of said throat.

11. The combination with a housing, of a down draft venturi mounted therein, and means separate therefrom for feeding fuel mixture into and through the same from above, of a well within said housing directly beneath the lower end of said venturi and spaced therefrom, a jet nozzle in the throat of said venturi, a conical bafiie in said housing extending within the discharge end of said venturi and projecting into said well to a point below the rim thereof, and a conduit within said housing extending from a point in said well under said baffle to said nozzle,

RALPH SHIPMAN. 

